At unfavorable I think 3♦ is insane. Way too easy to go for 200 here, and even 5 and 8 aren't out of the question, esp. if partner is on like xxx xxx xxxx xxx. Plus, who says 2♠ is making? At equal I would rarely bid 3♦, much more rarely still if 1N is weak. At favorable...hey, up to you, but I do think it's a bit of anti-partnership bid.